const { src, dest, series, parallel, watch } = require('gulp')
const loadPlugins = require('gulp-load-plugins');
const sass = require("gulp-sass")(require('sass'));
const plugins = loadPlugins();
const del = require('del');
const browserSync = require('browser-sync');
const bs = browserSync.create();

const data = {
    menus: [
      {
        name: 'Home',
        icon: 'aperture',
        link: 'index.html'
      },
      {
        name: 'Features',
        link: 'features.html'
      },
      {
        name: 'About',
        link: 'about.html'
      },
      {
        name: 'Contact',
        link: '#',
        children: [
          {
            name: 'Twitter',
            link: 'https://twitter.com/w_zce'
          },
          {
            name: 'About',
            link: 'https://weibo.com/zceme'
          },
          {
            name: 'divider'
          },
          {
            name: 'About',
            link: 'https://github.com/zce'
          }
        ]
      }
    ],
    pkg: require('./package.json'),
    date: new Date()
}

const clean = () => {
    return del(['dist', 'temp'])
}

const style = () => {
    return src('src/assets/styles/*.scss', { base: 'src' })
    .pipe(sass())
    .pipe(dest('temp'))
    .pipe(bs.reload({stream: true}))
}

const script = () => {
    return src('src/assets/scripts/*js', { base: 'src' })
    .pipe(plugins.babel({ presets:['@babel/preset-env'] }))
    .pipe(dest('temp'))
    .pipe(bs.reload({stream: true}))
}

// 加上cache:false 这样修改html也能热更新，不加更新不了有缓存
const page = () => {
    return src('src/*.html', { base: 'src' })
    .pipe(plugins.swig({ data, defaults: { cache: false }}))
    .pipe(dest('temp'))
    .pipe(bs.reload({stream: true}))
}

const image = () => {
    return src('src/assets/images/**', { base: 'src' })
    .pipe(plugins.imagemin())
    .pipe(dest('dist'))
}

const font = () => {
    return src('src/assets/fonts/**', { base: 'src' })
    .pipe(plugins.imagemin())
    .pipe(dest('dist'))
}

// 额外的文件
const extra = () => {
    return src('src/public/**', { base: 'public' })
    .pipe(dest('dist'))
}

const serve = () => {
    watch('src/assets/styles/*.scss', style);
    watch('src/assets/scripts/*js', script);
    watch('src/*.html', page);
    // watch('src/assets/images/**', image);
    // watch('src/assets/fonts/**', font);
    // watch('src/public/**', extra);
    // 在开发环境中增加构建速度，我们可以不对图片文字等任务进行编译，当我们修改了之后可以刷新浏览器
    watch([
        'src/assets/images/**',
        'src/assets/fonts/**',
        'src/public/**',
    ], bs.reload)
    /**
     * files 指定修改文件的路径，当文件被修改后，会刷新浏览器,可以在任务后面加上reload方法，就可以去掉files的监听
     */
    bs.init({
        notify: false,
        port: 3500,
        // files: 'dist/**',
        server: {
            baseDir: ['temp', 'src', 'public'],
            routes: {
                '/node_modules': 'node_modules'
            }
        }
    })
}

const useref = () => {
    return src('temp/*.html', { base: 'temp' })
    .pipe(plugins.useref({searchPath: ['temp', '.']}))
    // html js css
    .pipe(plugins.if(/\.js$/, plugins.uglify()))
    .pipe(plugins.if(/\.css$/, plugins.cleanCss()))
    .pipe(plugins.if(/\.html$/, plugins.htmlmin({
        collapseWhitespace: true,
        minifyCSS: true,
        minifyJS: true
      })))
    .pipe(dest('dist'))
}

const compile = parallel(style, script, page)

const build = series(clean, 
    parallel(series(compile, useref), 
    image, 
    font, 
    extra)); 

const dev = series(clean, compile, serve)

module.exports = {
    clean,
    build,
    dev,
}